do(does, did) 的用法

(1)构成疑问句或否定句

How did you know about it?你是怎样知道这件事的。

He does not smoke. 他不抽烟。

(2)加强语气。

He did tell that.他的确告诉了此事。

Do come and see us.一定来看我们。

(3)代替前面刚出现的动词，避免重复。

-You like popular music, don't you?你喜欢流行音乐，是吧?

-Yes , I do.是的，我喜欢。

He speaks French as fluently as she does.他讲法语和她讲的一样流利。

(4)用于倒装句中。

Never did he pay attention to my words.他从不注意我的话。

Only then did I understand the importance of English.只是那时，我才了解到英语的重要性。

(5)构成否定的祈使句。

Don't be so careless.不要那么粗心。

Do not hesitate to come for help.只管来求助。